BHATE Geosciences Corporation

SUE Investigation: ALDOT Central Business District Bridge Replacement on I-59/I-20 from I-65 to 31st St Project Number: IM-1059

October 29, 2014

ALDOT - Central Business District

I-59/I-20 from I-65 to 31st Street

Birmingham, Alabama

CBD Project Summary

ALDOT is planning bridges along Interstate 59/20 through the City of Birmingham’s Central Business District (CBD).

As part of the restructuring and rerouting and proposed new construction, detailed information on subsurface utilities was required for the planning and design.

The work includes approximately 1.5 miles of roadway and bridge widening on I-59/I-20 and I-65

Approximately 32 new bridges/ramps/bridge widening

Additionally, improvements to the I-59/20/31st Street North interchange, and the I-59/20.US 31(Red

Mountain Expressway) interchange are planned.

Utility Verification Prior to Borings

Geotechnical drilling included nearly 500 boring locations performed by multiple consultants

CBD is a highly urbanized and developed area (since late 1800’s) with multitude of utilities. It was necessary to verify that the proposed boring locations were free of subsurface high value utilities

This area consisted of gas, telephone, fiber-optic cables and other sensitive targets that could be significantly disrupted and impacted in case of damage during field exploration.

CBD Boring Locations

BHATE provided pre-drilling SUE services to locate the utilities and clear boring locations to manage subsurface conflicts and reduce risk of potential damage.

Approximately 500 boring locations scanned

Nearly 20% of the borings were impacted by subsurface utilities and had to be shifted.

O R O O

R R

CBD Boring Locations

Used geophysical methods to clear safe boring locations

Ground penetrating radar (GPR)

Cable and pipe locators

Note: Differences noted at numerous locations between actual and One Call marked utilities.

After scanning and relocation of the borings where conflicts were indicated, 100% of scanned borings were safely drilled.

Considerable potential cost savings in regards to interruptions in service and/or utility repair had this scanning not been done prior to commencing drilling. Information from available records and

One-Call could not be completely relied upon.

ALDOT Phase Prioritization

Phase I: 31st Street North and 12th Avenue North

Phase 2: I-59/I-20 and I-65 Interchange

Phase 3: 12th Court North

Phase 4: CBD Interchange Ramps

Phase 5: CBD Bridge Demo and Replacement

Why SUE???

Preconstruction Planning

Utility-related problems are a leading cause of delays that occur during the construction phase of highway projects (FHWA-IF-02-048)

Cost Management

For small fraction of total construction costs, initial SUE investigation can save significant costs caused by delays, repairs, change orders etc.

Utilities management

Accurately determine existing utilities and as-built conditions and depths

Address conflicts during design stage

Replace/relocate discussions with utility companies prior to final design completion

Avoid risks

Damage to utilities

Repairs

Disruptions in service

Safety

ALDOT SUE Objectives

“ALDOT realizes utility identification, relocation and management is critical information for project design and to give to the contractor”

Want nothing to slow or disrupt progress

Can’t stand any surprises!

“That is why ALDOT is going through this effort and have seen significant value in the SUE process for the CBD project”

Mr. Steve Walker, P.E. ROW- Engineer

Procedure for Accomplishing Field Work

General Outline

Four (4) main utility data quality levels established by American Society of Civil Engineers' Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data – ASCE 38-02

Provides a means of obtaining a professional opinion of the quality and reliability of utility information

Utility Quality Levels

QL-D

QL-C

QL-B

QL-A

Procedure for Accomplishing CBD Field Work

Records Research- QL-D – First Step

Gather and review available drawings and records. Included historical archives going back to late 1800’s.

Obtain available as-built information from Utilities, Alabama Gas, Alabama Power, Birmingham Waterworks etc.

Preliminary assessment of the types of utilities present in the area and their likely location and depth.

ATT will not provide information – only confirm if there is a conflict with a proposed construction activity

Field Observation- QL-C – Second Step

Visually inspect available surface indicators

Verify approximate depth and alignment of utilities present based on surface features

Geophysical Investigation- QL-B

Application of surface geophysical methods to determine the existence and position of utilities.

Ground penetrating radar (GPR)

Ferromagnetic Locators

RD 7000 cable and pipe locators

One Call locating services are also used. However, we often find discrepancies in lines located by these agencies and actual field conditions.

SUE Level B Field Work This included in-situ verification of utilities using GPR and other NDT methods

SUE ‘Level B’ Field Equipment

Ground-Penetrating Radar– multiple SIR 3000 utility carts by GSSI. Multiple antenna frequencies available.

Multi-channel GPR system - a 14-channel- cart-based ground penetrating radar unit that is typically towed behind a vehicle during survey operations.

Optical Equipment- using visible light as an electromagnetic method. For example, using a laser through a pipe from one vault to another. FLIR ThermaCAM EX320 infrared cameras

RD7000 cable and pipe locators and Tx transmitter - induces a frequency into a buried pipe or cable and allows the user trace out the alignment of the utility on the ground surface

Ferro magnetic locators- locating and pinpointing buried metal objects such as manholes and metallic pipes

Actual Exposure- QL-A

This level was implemented in limited areas where Level B information was limited and high risk underground utilities required in-place exposure and verification of type and depths.

Highest level of accuracy available

Nondestructive exposure of underground utilities

Employed minimally intrusive excavation equipment (vacuum extraction) to minimize the potential for utility damage

Type, size, depth, and location of utilities were recorded and used to verify provided information

Depth of exposure ranged from 3’ to 5’

Level ‘A’ Field Work

SUE Process Workflow

CBD Bridge Demolition and Replacement

I-59/I-20 and I-65 Interchange - Findings

Site Specific Findings I-59/I-20 and I-65 Interchange

Records Review QL-D - Sanborn Maps and other sources revealed:

Oil Refinery

Dry Cleaners

Birmingham Electric Co.

Foundry, Machine Shop, Storage Yard

10-15 Tanks were identified

Multitude of old utilities – it was unknown which utilities were abandoned.

Site Specific Findings I-59/I-20 and I-65 Interchange

QL-D and QL-C investigation uncovered numerous inconsistencies.

Utility records from Alabama Power, Jefferson County Environmental Services and Water Works did not match in-field conditions. Manhole covers not found in the field but present on the utility records.

Information on abandoned and active utilities was not clearly documented and would require further verification.

Utilities marked in the field by One-Call were not consistent with the records provided by utilities.

Level B SUE work is pending and will be implemented in this area and supplemented by Level A, as necessary.

CBD Bridge Demolition and Replacement

23rd Street to 31st Street North Section -

Findings

Site Specific Findings

23rd Street to 31st Street North

QL-D and QL-C also uncovered discrepancies

Historical records as well as Sanborn maps indicated old gas stations, a railroad yard with multiple tracks etc.

Utility records and surface features indicated that the drawings provided by utility companies did not accurately reflect in-ground conditions.

Site Specific Findings 23rd Street to 31st Street North

QL-B investigation was performed to verify the location of buried utilities beneath proposed CBD bridge alignment

Identified locations of buried railroad tracks. These were covered up by existing pavement with no visible signs on the surface.

The entire area was mapped in detail at each intersection. Numerous undocumented underground utilities were found.

Discrepancies between utility drawings and actual locations were resolved. Conflicts between actually existing utilities and proposed construction were identified.

CBD Bridge Demolition and Replacement

9th Ave from 15th St to 23rd St – Findings

Site Specific Findings 9th Ave from 15th St to 23rd St

QL-D and QL-C investigation revealed various discrepancies.

Utility records and as built drawings of sewer, electrical, water, gas, steam, etc., were inconsistent with in-field surface

indicators.

QL-B investigation was performed to verify the location of buried utilities beneath the proposed CBD bridge alignment

The entire area of interest was mapped in detail. Numerous underground utilities were verified at each intersection and right of way.

Conflicts between actually existing utilities and proposed

construction were identified.

Site Specific Findings 9th Ave from 15th St to 23rd St

QL-A was performed on a 115 KV oil-cooled electrical

transmission line and 30 inch main water line

Actual location, depth, material and condition was verified for the proposed CBD construction plans.

Further QL-A was needed and currently in progress along 9th Ave. N

QL-A Along 9th Avenue North

Data Management Procedure Upon completion of QL-B and QL-A, Volkert surveyed the

alignment and depth of target utilities identified and marked in the field by BHATE. Deliverables included the following:

Plan/Profile sheets and Cross Sections showing utility locations.

Depict information using ALDOT CADD Standards and Plan Preparation Manual.

Developed a conflict matrix showing all possible known utility conflicts with the proposed construction.

The findings are reviewed with ALDOT for Impact Assessment.

Areas selected for further exploration using Level A assessment.

Summary

BHATE mapped the location of utilities using a combination of provided drawings from utility companies and historical research.

Compared the results of the subsurface utility survey to the field features and drawings to validate the available information and resolve differences in the information from QL-D, QL-C and QL-B.

When necessary, conducted additional searches and performed field operations to clear discrepancies between records and subsurface survey.

When necessary, exposed selected subsurface utilities to obtain three-dimensional information using minimally invasive methods. QL-A. Resolve discrepancies and update drawings.

The SUE process implemented for the CBD project revealed information that was undocumented or unknown and will now significantly aid in the final design, conflict resolution with underground utilities or remnants from other developments in this area over the past 100+ years.

BHATE Team on the CBD SUE Project

Uday R. Bhate, P.E., Senior Principal

Marc Langlois, P.G., Senior SUE Manager

Jeremiah Bishop, M.S., Project Manager

Jordan Middleton, B.S.C.E., Manager Field Services

Chuck Grostick, B.S., Certified Senior GPR/SUE Technician

Sarah Samples, Project Information Coordinator

SUE Resources and Reference Documents

FHWA-Utility Relocation and Accommodation on Federal-Aid Highway Projects- January 2003

Provides Guidelines and Basis for: Utility Accommodation Utility Relocations, Adjustments and Reimbursements Communication of Utility Data Risk and Impact Analysis Cost Estimate Procedures Other Issues

ASCE Standard CI/ASCE 38-02

Quality Levels in Subsurface Utility Engineering as a Basis for:

•Accurate Knowledge of Horizontal and Vertical Location •Data Management and Depiction of Utilities on Construction Plans Prior to Excavation •Design Around Underground Utilities to Avoid Costly Relocations

ALDOT Utilities Manual

QUESTIONS???